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ulbador

macrumors 68000
Feb 11, 2010
1,554
0
You cannot successfully format an 800 Kb floppy to 1.4, nor 1.4 to 800.

False on both counts, I used to do it all the time.

You can turn the 800 into a 1.4 by drilling a second hole. The biggest problem was often the reason they were formatted to 800kb is because at 1.4 they had sector errors. Going for 1.4 to 800kb (or 720k on a PC) was entirely software dependent. I believe DOS used to let you do it without doing anything special. To do the same on a Mac, you had to cover up the second hole with some tape.

I had to do this all the time when the number of disks I owned was limited and the different computers I had access to contained different capacity drives.
 

luisreg

macrumors newbie
Dec 19, 2012
3
0
Ideas?

I'm on OSX Lion with a working Floppy USB unit and brand new 3 1/2 disks, trying to install OS 7.0.1 on a Macintosh Classic with a new drive (no current installed OS).

I ran the following command on terminal: dd if=~/OS7/os-6-1.img of=/dev/disk1 bs=84 skip=1

It completes succesfully, but then I encounter the following problems:

1) If I try to re-mount on Disk Utility, it returns an error message saying it cannot be mounted.
2) If I eject it after the terminal command, it says I have to initialize it, because it's not formatted (??)
3) If I start my Macintosh Classic with it, it ejects it and doesn't recognize it as an installation disk.

Any ideas?

Thanks!
Luis
 
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